Safety crank for engines



Patented Nov, 7, 192.2.

WACLAVY POKRZYWA, JDSEF .l. .A.T'YG1?- AND STE "\K ISCONSIN.

SAFETY OEJANK EEL'GINES.

Application filed .a i-n s5,

To all whom it may concern.

Be it known that we, VVACLAW Ponnzrva, J osnr MA'rYeA, and STEPHEN Lnwaivnowsnr, all citizens of the United States, and residents of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Safety Cranks for Engines; and we do hereby declare that the following is a full, clear, and exact description thereof.

Our invention relates to an improved safety crank, designed especially for crani=zing engines of the internal combustion type.

The general object of the invention is to provide a structure by means of which the danger of injury due to a premature explosion before the engine crank has passed the dead center isentirely eliminated.

The invention consists further in certain details of construction and combinations thereof which will be more particularly de scribed in connection with the accompanying drawing and subsequently claimed.

In the drawing:

Figure 1 is a longitudinal sectional view of our invention.

Figure 2 is a front elevation thereof, with the cover removed.

Figure 3 is a longitudinal section thereof taken at right angles to the plane of Figure 1.

Referring in detail to the drawing sunreral 5 designates a hollow shank in one end of which is journaled a handle 6. having a reduced portion 7 which is retained by a suitable collar 8 or equivalent fastening device.

The other end of the shank 5 i provided with an enlarged head 9, centrally of which is journaled a spindle 10, having at its outer end a socket 11 for engaging the crank shaft of the engine.

The head 9 is formed with an enlarged internal recess 12 into which projects the squared end 13 of the spindle 10. A cog wheel 14 is carried by the projecting end 1% and secured thereon by a cotter pin or the like 15, which is retained in position by a spacing block 16, which is countersunk in the head 9, as shown at 17 in Figure 2. These parts are retained within the head a by means of a cover plate 18 which is prosteel 24 which is carried around the wheel 1% and aromded with an enlar red end Serial No. 556,384.

vided with depending angular lugs 19, which are engaged in bayonet slots 20 formed in the head.

A. flexible cord or cable 21 is suitably se- 7 cured in the reduced portion 7 of the handle by any suitable means. such for example as indicated by the knot end 22 in Figure 1. The reduced portion 7 is also provided with a circumferential groove 23 within. which the cord 21 is laid as the handle 6 rotated. The other end of the cord 21 is suitably secured to flat stripof spring cos r-ving teeth 25 adapted :eeth of the wheel.

to ensa e with the in the operation of our invention it will be understoocL that the operator will grip the handle 6, and in turning the crank the handle will be graduall -J rotated, thus wind-- ing the cord 21 around the reduced end '7 and laying the same in the groove 23. This operation will shorten the elfective length of the cord and draw the strip 24.- inwardly. causing t tee h 25 to engage the wheel 14.- and lock the same to the crank Thereupon, revolution of the crank will turn the If, however, a premature explosion takes place the wheel will turn backwardly, jerking upon the cord 21, and the head 25 will be thrown backwardly into the corner 26 of the re ess 12 and disengage the whee 1 1 from the card: and permit the same to revolve 1 y. The shank 5 is thereby released from the spindle l0 and socket 1.1 and all danger of injury to the person using the crank is thereby eliminated.

Although we have shown and described speci ically one construction by means of which our invention may be carried out it will. be understood that various modiiica tions may be made in the details thereof without departing from the spirit of the invention.

Vi e claim as our invention the following:

The combination with a crank a hollow shank. of a socket member ournaled in one end of the shank. handle journaled in the other end thereof. a cog wheel keyed to the socket member and housed within the crank, and a flexible member within the 'T rinwnnnowsni, rarnwauiinn,

we have hereunto set our hands at Milwaukee, in the'county of Milwaukee, and State of WVisconsin.

WVACLAWV POKRZYVVA. JOSEF MATYGA. STEPHEN LEWANDOWSKL 

